Mercouri Kanatzidis and co-workers, Northwestern University, USA, have incorporated nanocrystals of rock salt (SrTe) into lead telluride to create a new material which can generate electricity from heat more efficiently than previous materials.

Nanostructuring in bulk materials reduces thermal conductivity but simultaneously increases scattering of electrons, thos reduces overall conductivity. With endotaxially arranged nanocrystals, the team have shown that the thermal and electron transport properties are decoupled and the material reaches a thermoelectric figure of merit of 1.7 at ~800 K.

Inclusion of this material into devices such as vehicle exhaust systems, light bulbs, or industrial processes, where heat is generated as a by-product, could allow up to 15 % of this wasted energy to be recycled.

• Strained endotaxial nanostructures with high thermoelectric figure of merit
  K. Biswas, J. He, Q. Zhang, G. Wang, C. Uher, V. P. Dravid, M. G. Kanatzidis,
  Nat. Chem. 2011.
  DOI: 10.1038/nchem.955